however, the wried thing is, sometimes the moving is successful and other times it give me the following exception

[code]Java Model Exception: Core Exception [code 4] Problems encountered while moving resources.
at org.eclipse.jdt.internal.core.MultiOperation.processElements(MultiOperation.java:175)
at org.eclipse.jdt.internal.core.CopyResourceElementsOperation.processElements(CopyResourceElementsOperation.java:417)
at org.eclipse.jdt.internal.core.MultiOperation.executeOperation(MultiOperation.java:90)
at org.eclipse.jdt.internal.core.JavaModelOperation.run(JavaModelOperation.java:728)
at org.eclipse.core.internal.resources.Workspace.run(Workspace.java:1975)
at org.eclipse.jdt.internal.core.JavaModelOperation.runOperation(JavaModelOperation.java:793)
at org.eclipse.jdt.internal.core.JavaModel.rename(JavaModel.java:285)
at org.eclipse.jdt.internal.core.PackageFragment.rename(PackageFragment.java:432)
at newmodulewizrd.ui.Integrate.printPackageInfos(Integrate.java:234)
at newmodulewizrd.ui.Integrate.printProjectInfo(Integrate.java:157)
at newmodulewizrd.ui.Integrate.getWorkSpace(Integrate.java:139)
at newmodulewizrd.ui.Integrate.moveToOneModule(Integrate.java:117)
at newmodulewizrd.ui.Integrate$1.actionPerformed(Integrate.java:87)
at javax.swing.AbstractButton.fireActionPerformed(AbstractButton.java:1995)
at javax.swing.AbstractButton$Handler.actionPerformed(AbstractButton.java:2318)
at javax.swing.DefaultButtonModel.fireActionPerformed(DefaultButtonModel.java:387)
at javax.swing.DefaultButtonModel.setPressed(DefaultButtonModel.java:242)
at javax.swing.plaf.basic.BasicButtonListener.mouseReleased(BasicButtonListener.java:236)
at java.awt.Component.processMouseEvent(Component.java:6288)
at javax.swing.JComponent.processMouseEvent(JComponent.java:3267)
at java.awt.Component.processEvent(Component.java:6053)
at java.awt.Container.processEvent(Container.java:2041)
at java.awt.Component.dispatchEventImpl(Component.java:4651)
at java.awt.Container.dispatchEventImpl(Container.java:2099)
at java.awt.Component.dispatchEvent(Component.java:4481)
at java.awt.LightweightDispatcher.retargetMouseEvent(Container.java:4577)
at java.awt.LightweightDispatcher.processMouseEvent(Container.java:4238)
at java.awt.LightweightDispatcher.dispatchEvent(Container.java:4168)
at java.awt.Container.dispatchEventImpl(Container.java:2085)
at java.awt.Window.dispatchEventImpl(Window.java:2478)
at java.awt.Component.dispatchEvent(Component.java:4481)
at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:643)
at java.awt.EventQueue.access$000(EventQueue.java:84)
at java.awt.EventQueue$1.run(EventQueue.java:602)
at java.awt.EventQueue$1.run(EventQueue.java:600)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.AccessControlContext$1.doIntersectionPrivilege(AccessControlContext.java:87)
at java.security.AccessControlContext$1.doIntersectionPrivilege(AccessControlContext.java:98)
at java.awt.EventQueue$2.run(EventQueue.java:616)
at java.awt.EventQueue$2.run(EventQueue.java:614)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.AccessControlContext$1.doIntersectionPrivilege(AccessControlContext.java:87)
at java.awt.EventQueue.dispatchEvent(EventQueue.java:613)
at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:269)
at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:184)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:174)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:169)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:161)
at java.awt.EventDispatchThread.run(EventDispatchThread.java:122)
Caused by: org.eclipse.core.internal.resources.ResourceException: Problems encountered while moving resources.
at org.eclipse.core.internal.resources.Resource.move(Resource.java:1609)
at org.eclipse.core.internal.resources.Resource.move(Resource.java:1558)
at org.eclipse.jdt.internal.core.CopyResourceElementsOperation.processPackageFragmentResource(CopyResourceElementsOperation.java:468)
at org.eclipse.jdt.internal.core.CopyResourceElementsOperation.processElement(CopyResourceElementsOperation.java:403)
at org.eclipse.jdt.internal.core.MultiOperation.processElements(MultiOperation.java:163)
... 48 more
Caused by: org.eclipse.core.internal.resources.ResourceException: Problems encountered while moving resources.
at org.eclipse.core.internal.resources.Resource.move(Resource.java:1609)
at org.eclipse.core.internal.resources.Resource.move(Resource.java:1558)
at org.eclipse.jdt.internal.core.CopyResourceElementsOperation.processPackageFragmentResource(CopyResourceElementsOperation.java:468)
at org.eclipse.jdt.internal.core.CopyResourceElementsOperation.processElement(CopyResourceElementsOperation.java:403)
at org.eclipse.jdt.internal.core.MultiOperation.processElements(MultiOperation.java:163)
at org.eclipse.jdt.internal.core.CopyResourceElementsOperation.processElements(CopyResourceElementsOperation.java:417)
at org.eclipse.jdt.internal.core.MultiOperation.executeOperation(MultiOperation.java:90)
at org.eclipse.jdt.internal.core.JavaModelOperation.run(JavaModelOperation.java:728)
at org.eclipse.core.internal.resources.Workspace.run(Workspace.java:1975)
at org.eclipse.jdt.internal.core.JavaModelOperation.runOperation(JavaModelOperation.java:793)
at org.eclipse.jdt.internal.core.JavaModel.rename(JavaModel.java:285)
at org.eclipse.jdt.internal.core.PackageFragment.rename(PackageFragment.java:432)
at newmodulewizrd.ui.Integrate.printPackageInfos(Integrate.java:234)
at newmodulewizrd.ui.Integrate.printProjectInfo(Integrate.java:157)
at newmodulewizrd.ui.Integrate.getWorkSpace(Integrate.java:139)
at newmodulewizrd.ui.Integrate.moveToOneModule(Integrate.java:117)
at newmodulewizrd.ui.Integrate$1.actionPerformed(Integrate.java:87)
at javax.swing.AbstractButton.fireActionPerformed(AbstractButton.java:1995)
at javax.swing.AbstractButton$Handler.actionPerformed(AbstractButton.java:2318)
at javax.swing.DefaultButtonModel.fireActionPerformed(DefaultButtonModel.java:387)
at javax.swing.DefaultButtonModel.setPressed(DefaultButtonModel.java:242)
at javax.swing.plaf.basic.BasicButtonListener.mouseReleased(BasicButtonListener.java:236)
at java.awt.Component.processMouseEvent(Component.java:6288)
at javax.swing.JComponent.processMouseEvent(JComponent.java:3267)
at java.awt.Component.processEvent(Component.java:6053)
at java.awt.Container.processEvent(Container.java:2041)
at java.awt.Component.dispatchEventImpl(Component.java:4651)
at java.awt.Container.dispatchEventImpl(Container.java:2099)
at java.awt.Component.dispatchEvent(Component.java:4481)
at java.awt.LightweightDispatcher.retargetMouseEvent(Container.java:4577)
at java.awt.LightweightDispatcher.processMouseEvent(Container.java:4238)
at java.awt.LightweightDispatcher.dispatchEvent(Container.java:4168)
at java.awt.Container.dispatchEventImpl(Container.java:2085)
at java.awt.Window.dispatchEventImpl(Window.java:2478)
at java.awt.Component.dispatchEvent(Component.java:4481)
at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:643)
at java.awt.EventQueue.access$000(EventQueue.java:84)
at java.awt.EventQueue$1.run(EventQueue.java:602)
at java.awt.EventQueue$1.run(EventQueue.java:600)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.AccessControlContext$1.doIntersectionPrivilege(AccessControlContext.java:87)
at java.security.AccessControlContext$1.doIntersectionPrivilege(AccessControlContext.java:98)
at java.awt.EventQueue$2.run(EventQueue.java:616)
at java.awt.EventQueue$2.run(EventQueue.java:614)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.AccessControlContext$1.doIntersectionPrivilege(AccessControlContext.java:87)
at java.awt.EventQueue.dispatchEvent(EventQueue.java:613)
at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:269)
at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:184)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:174)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:169)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:161)
at java.awt.EventDispatchThread.run(EventDispatchThread.java:122)
Contains: Could not move: C:\Users\ARIFAH\Downloads\Compressed\eUML2 free version\runtime-EclipseApplication\aC\src\t1.
org.eclipse.core.runtime.CoreException: Problems encountered while deleting files.
at org.eclipse.core.internal.filesystem.local.LocalFile.delete(LocalFile.java:125)
at org.eclipse.core.filesystem.provider.FileStore.move(FileStore.java:408)
at org.eclipse.core.internal.filesystem.local.LocalFile.move(LocalFile.java:352)
at org.eclipse.core.internal.localstore.FileSystemResourceManager.move(FileSystemResourceManager.java:664)
at org.eclipse.core.internal.resources.ResourceTree.standardMoveFolder(ResourceTree.java:995)
at org.eclipse.core.internal.resources.Resource.unprotectedMove(Resource.java:1969)
at org.eclipse.core.internal.resources.Resource.move(Resource.java:1597)
at org.eclipse.core.internal.resources.Resource.move(Resource.java:1558)
at org.eclipse.jdt.internal.core.CopyResourceElementsOperation.processPackageFragmentResource(CopyResourceElementsOperation.java:468)
at org.eclipse.jdt.internal.core.CopyResourceElementsOperation.processElement(CopyResourceElementsOperation.java:403)
at org.eclipse.jdt.internal.core.MultiOperation.processElements(MultiOperation.java:163)
at org.eclipse.jdt.internal.core.CopyResourceElementsOperation.processElements(CopyResourceElementsOperation.java:417)
at org.eclipse.jdt.internal.core.MultiOperation.executeOperation(MultiOperation.java:90)
at org.eclipse.jdt.internal.core.JavaModelOperation.run(JavaModelOperation.java:728)
at org.eclipse.core.internal.resources.Workspace.run(Workspace.java:1975)
at org.eclipse.jdt.internal.core.JavaModelOperation.runOperation(JavaModelOperation.java:793)
at org.eclipse.jdt.internal.core.JavaModel.rename(JavaModel.java:285)
at org.eclipse.jdt.internal.core.PackageFragment.rename(PackageFragment.java:432)
at newmodulewizrd.ui.Integrate.printPackageInfos(Integrate.java:234)
at newmodulewizrd.ui.Integrate.printProjectInfo(Integrate.java:157)
at newmodulewizrd.ui.Integrate.getWorkSpace(Integrate.java:139)
at newmodulewizrd.ui.Integrate.moveToOneModule(Integrate.java:117)
at newmodulewizrd.ui.Integrate$1.actionPerformed(Integrate.java:87)
at javax.swing.AbstractButton.fireActionPerformed(AbstractButton.java:1995)
at javax.swing.AbstractButton$Handler.actionPerformed(AbstractButton.java:2318)
at javax.swing.DefaultButtonModel.fireActionPerformed(DefaultButtonModel.java:387)
at javax.swing.DefaultButtonModel.setPressed(DefaultButtonModel.java:242)
at javax.swing.plaf.basic.BasicButtonListener.mouseReleased(BasicButtonListener.java:236)
at java.awt.Component.processMouseEvent(Component.java:6288)
at javax.swing.JComponent.processMouseEvent(JComponent.java:3267)
at java.awt.Component.processEvent(Component.java:6053)
at java.awt.Container.processEvent(Container.java:2041)
at java.awt.Component.dispatchEventImpl(Component.java:4651)
at java.awt.Container.dispatchEventImpl(Container.java:2099)
at java.awt.Component.dispatchEvent(Component.java:4481)
at java.awt.LightweightDispatcher.retargetMouseEvent(Container.java:4577)
at java.awt.LightweightDispatcher.processMouseEvent(Container.java:4238)
at java.awt.LightweightDispatcher.dispatchEvent(Container.java:4168)
at java.awt.Container.dispatchEventImpl(Container.java:2085)
at java.awt.Window.dispatchEventImpl(Window.java:2478)
at java.awt.Component.dispatchEvent(Component.java:4481)
at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:643)
at java.awt.EventQueue.access$000(EventQueue.java:84)
at java.awt.EventQueue$1.run(EventQueue.java:602)
at java.awt.EventQueue$1.run(EventQueue.java:600)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.AccessControlContext$1.doIntersectionPrivilege(AccessControlContext.java:87)
at java.security.AccessControlContext$1.doIntersectionPrivilege(AccessControlContext.java:98)
at java.awt.EventQueue$2.run(EventQueue.java:616)
at java.awt.EventQueue$2.run(EventQueue.java:614)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.AccessControlContext$1.doIntersectionPrivilege(AccessControlContext.java:87)
at java.awt.EventQueue.dispatchEvent(EventQueue.java:613)
at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:269)
at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:184)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:174)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:169)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:161)
at java.awt.EventDispatchThread.run(EventDispatchThread.java:122)
Contains: Could not delete: C:\Users\ARIFAH\Downloads\Compressed\eUML2 free version\runtime-EclipseApplication\aC\src\t1\t1CommonInterface.java.
Contains: Could not delete: C:\Users\ARIFAH\Downloads\Compressed\eUML2 free version\runtime-EclipseApplication\aC\src\t1\t1Description.java.
Contains: Could not delete: C:\Users\ARIFAH\Downloads\Compressed\eUML2 free version\runtime-EclipseApplication\aC\src\t1\t1MIDetail.java.
Contains: Could not delete: C:\Users\ARIFAH\Downloads\Compressed\eUML2 free version\runtime-EclipseApplication\aC\src\t1\t1MomentInterval.java.
Contains: Could not delete: C:\Users\ARIFAH\Downloads\Compressed\eUML2 free version\runtime-EclipseApplication\aC\src\t1\t1PartyPlaceThing.java.
Contains: Could not delete: C:\Users\ARIFAH\Downloads\Compressed\eUML2 free version\runtime-EclipseApplication\aC\src\t1\t1Person.java.
Contains: Could not delete: C:\Users\ARIFAH\Downloads\Compressed\eUML2 free version\runtime-EclipseApplication\aC\src\t1\t1Role.java.
Contains: Could not delete: C:\Users\ARIFAH\Downloads\Compressed\eUML2 free version\runtime-EclipseApplication\aC\src\t1.
[/code]

when i used google for this problem, i found out this exception was reported as bug but was a verified fixed in eclipse galileo.

i would like to know what can i do in order to avoid this exception. it is my thesis submission on 24th dec and i need to do a lot of testing before it, so i would like to know what can i do in this regard.